Straining arrangement in vacuum drying apparatus



June 27, 1933. E, JONSSON STRAINING ARRANGEMENT IN VACUUM DRYING APPARATUS Filed Sept. 9, 1931 AUGUSTINUS EDVARD JONSSON INVENTOR BY ,M

ATTORNEYS Patented June 27, 1933 I UNITED STATES AUGUSTINUS EDVARID JONSSON', OF DALTORP, LIDINGQ, SWEDECN STRAINING ARRANGEMENT IN VACUUM-DRYING ArrAeArUs Application filed September 9, 1931 Serial No. 561,844, and in Sweden September 25, 1936.

holder mounted to rotate in relation to the 15 hollow body and eccentrically weighted.

Said holder is, further, provided with cleansing teeth or projections corresponding to the number of the slots and extending into the latter. At the rotation of the drum and,

thus, of the hollow body, said teeth are displaced in said slots. 7

In such straining arrangements it has, however, been found that the impurities, which have entered the straining slots, are not entirely removed at the displacement of the cleansing-teeth in the slots, as said impurities are forced, by the cleansing-teeth, towards the ends of the slots. On account of this fact the impurities are, more and more, pressed together in the slots, which finally will, by this fact, be completely stopped up.

To avoid this inconvenience, according to this invention, the hollow body is, at the ends of the straining slots, provided with recesses running radially inwards. In the sides of these recesses the straining slots are cut down to a depth somewhat larger than that which corresponds to the height of the cleansing teeth extending into the straining slots so as to allow said teeth, when going into said recesses, to push out the impurities gathered in the slots.

The annexed drawing shows an embodiment of the arrangement according to the 5 invention.

Fig. 1 is a longitudinal section through the arrangement on the line I-I in Fig. 2. Fig. 2 is a cross-section on the line II-II in Fig. 1.

Referring to the drawing, 1 is an end wall of the drying-drum at which the hollow body I or the holder 3 of the tubul'arpiece 2 are attached, for instance by means of boltsAt. That end of the tubular piece that is connected with the holder is open, as shown, the opposite end of the tubular piece being closed-55 by means of a wallb connected with the tubular piece 2. Said. wall 5 has its center provided with a recess adapted to receive a pin 7 arranged on a bracket 6. The tubular piece 2 is provided with straining slots 8 running 60 peripherally and extending along parts of the circumference of the tubular piece. Two rings 9 are arranged at the ends of the tubular piece 2, which rings are mounted toturn on the tubular piece.

Further, said rings are interconnected by a suitable number of cross-bars 10 being provided with a number of cleansing-teeth 11 corresponding to the number of the straining slots. The cleansing-teeth 11 extend into the '10 straining slots 8 and are adapted to be displaced in said slots at the rotation or oscillation of the drum. To this purpose, a projection 12 extends from each ring 9, said projections 12 together carrying a weight 13 at-=q5 tached by means of'bolts 14.

When the tubular piece 2 is put into communication with the source of vacuum, the vapors and gases, produced in the dryin drum, are sucked off through the straining- '30 slots 8 of the tubular piece and are removed in a suitable way. At this occasion, a part of the impurities, dust or the like emanating from the mass to be dried will, however, easily enter the straining-slots so that the latter"-h5 will run risk of being stopped up. However, by rotating the drying-drum, the cleansingteeth 11 are, by the influence of the weighted holder 12, 13, imparted a movement relatively to the slots, thus causing them to beiJO cleansed.

It may be suitable to arrange the working surfaces of the cleansing-teeth 11 in such a way as shown in Fig. 2, that-is-to-say, obliquely. By this fact, the cleansing-teeth, at bli the same time as they displace, peripherally, the matter located in the slots, they will also force it to move radially outwards.

The above-described straining device is in its main features already disclosed in my 100 :11 iii said recesses running continuouslyinthe lonl 'tudinal direction of the tubularpiece and in atransverse direction to the straining slots which extend to andcommunicate with the recesses in such a way that the cleansingteeth during the above described relativemotion can enter into said recesses, thus pushing before ,themand into said recesses any gathering impurities that otherwise would tend to accumulate at the ends of the straining slots. cleansing-teeth into the recesses 15, the slots 8 are cut down in the walls of the recesses to a'depth somewhat larger than that which corresponds to the height of the cleansing-teeth extending into the straining slots. r v

FAs illustrated in the lower part of-Fig. 1, the recesses 15 are in'substantiallytheirentire length open towards the interior of the drying drum "forming longitudinal pockets with the bottom 16, wherebyv any impurities pushed into them by the'cleansing-teeth in the described way will automatically drop off during the rotating 'or oscillating motion ofthe drying drum. r

The device described and illustrated is to be considered only as an embodiment, and the invention may also be applied inmany other ways without departing from the scope of the invention 1 Having now particularly described the nature of my invention and the manner of its operation, what I claim is a r a To facilitate said entrance of the 1. In vacuum drying apparatus provided with a rotatable drying drum a straining device comprising a hollow body arranged in said" drying drum and connected with a source of vacuum, straining slots provided on the circumference of said hollow body, cleansing-teeth projecting into said straining slots, means for imparting a relativemotion between said teeth and said slots in the longitudinal direction of the latter so as to re move'imp'urities tending to gather in said slots, and recesses provided in the surface of said hollow body running continuously in a transverse direction to said straining slots and communicating with the latter in such a way that said cleansingteeth can enter into said recesses andthus cleanse the straining slots. c I

J 2,-Invacuum drying apparatus provided with a rotatable drying drum a straining device comprising a hollow body arranged in said drying drum and connected with a 'source of vacuum, straining slots provided on the circumference of said hollow body, cleansing-teeth projecting into said straining slots, means for imparting a relative motion between said teeth and said slots in the longitudinal direction of the latter so as to remove impurities tending to gather in said slots, recesses provided in the surface of said hollow body running continuously in a transverse direction to said straining slots and communicating with the straining slots as well as a Y with the interior of the drying drum, said communications being so adapted that the cleansing-teeth can enter into said recesses thereby cleansing the straining slots and that impurities pushed into the recesses by the cleansing-teeth will automatically drop off.

' YAUGUSTINUSAEVDVAIRD JONSSON. 

